Seat construction



June 8, 1965 H. SCHNEIDER SEAT CONSTRUCTION Filed March 13, 1963 2 Sheets-Sheet 1 INVENTOR. fifi'za'll jc flel ien Jun 8, 1965 H. SCHNEIDER 3,188,073

SEAT CONSTRUCTION Filed March 13, 1963 2 Sheets-Sheet 2 United States Patent Ofiice 3 ,188,073 Patented June 8, 1965 3,188,073 SEAT CONSTRUCTIQN Herbert Schneider, Dusseldorf-Holthansen, Germany, assignor, by mesne assignments, to American Metal Products Company, Detroit, Mich, a corporation of Michigan Filed Mar. 13, 1963, Ser. No. 264,9 9 Claims. (Cl. 267-80) This invention relates to seat constructions such as chair seats and the like and, more particularly, to structures of this type wherein the means for assembling the spring unit and frame approach the ultimate in structural simplicity.

While the invention has been shown and will be described in connection with a chair seat, it will be readily apparent that the invention finds utility when used in connection with other types of seats and also in the backs of chairs, davenports, and the like.

The invention will be described in connection with a spring unit of the type shown in the patent to Karl Kaden, Reissue Number 21,263, although, obviously, it may be employed in connection with any other type of flat spring.

A principal object of the invention is to provide a onepiece spring and a frame therefor provided with means whereby the spring and frame may be secured in assembled relation without the use of separate fastening means.

Another important object of the invention is to provide a structure of this type in which the inherent resilience of the spring unit acts to hold the spring unit and frame in assembled relation.

A further object of the invention is to provide a construction of this type in which the spring unit may be quickly and easily assembled with the frame without the use of elaborate or costly fixtures and tools.

A still further object is to provide a seat construction of this type in which the supporting or anchoring means on the frame is provided with means to prevent excessive deflection, under load, of the spring unit.

The above and other objects and advantages of the invention are obtained by providing a flat sinuous spring unit and a frame having opposed wedge-shaped grooves or rabbets in two sides thereof with the open ends of thegrooves confronting one another. The spring unit is slightly longer than the distance between the bases of the grooves and is compressed longitudinally and bowed sufficiently so that the ends of the spring unit may be inserted into the open ends of the grooves. When the spring unit is released, the ends thereof become wedgedly engaged with the walls of the grooves to hold the spring unit in assembled relation with the frame without the use of separate fastening means.

The various objects and advantages, and the novel details of construction of three commercially practical embodiments of the invention, will become more apparent as this description proceeds, especially when considered in connection with the accompanying drawings, in which:

FIGURE 1 is a top plain view of a chair seat constructed in accordance .with this invention, the usual insulating pad and upholstery padding being omitted;

FIGURE 2 is a transverse sectional view taken substantially on the plane indicated by line 22 in FIG- URE 1;

FIGURE 3 is an enlarged detail sectional view of the portion enclosed by a circle in FIGURE 2;

FIGURE 4 is a view similar to FIGURE 1 showing a slightly modified form of spring unit; and

FIGURE 5 is a view similar to FIGURE 1 showing another modified form of spring unit.

The spring device of this invention is formed by sinuously bending a suitable spring wire into adjacent oppositely disposed loops 11 and 12 which are joined together by straight portions 13. The spring device 1!) may be formed of one continuous length of wire, as illustrated, or, if desired, it may be formed of separate strips. It is preferable, however, to form the spring device 10 as one unit so that its assembly with the frame member, yet to be described, is simplified.

In the manufacture of the device, the loops are usually formed in one continuous straight length which is subsequently cut to length and bent to form the plurality of integrally connected strips which comprise the spring, as shown in FIGURE 1.,

The spring 10, as shown in FIGURE 1, is provided with a pair of supporting or anchoring end portions 14 at one end and a similar supporting or anchoring portion 15 at the other end. The ends 16 of the spring device 10 are arranged in longitudinal alignment with the portion 15 and also function as supporting or anchoring portions for the spring device 10.

Each of the supporting or anchoring portions 14 and 15 may be formed by bending or straightening out one of the loops 11 or 12 and the ends 16 are provided by straightening out a portion of a loop adjacent a straight portion 13, during the formation of the spring unit 10. In bending the wire, as above described to form the spring unit 10, the strips of loops are positioned in spaced, parallel relation with the loops thereof oppositely disposed, as shown in FIGURE 1.

The reference character 20, indicates a seat or back frame with which the spring device 10 is adapted to be assembled. The frame 20 comprises a pair of spaced parallel end members 21 connected by side frame members 22. These frame members 21 and 22 may be secured together in any suitable manner such, for instance, as by means of dowels 23.

A pair of frame members, for instance the end frame members 21, are provided at the inner edges thereof with opposed rabbets or grooves 25 adapted to receive and to anchor and support the spring unit 10. One wall 26 of the rabbet or groove is arranged in a horizontal plane or parallel to the top and bottom outer faces of the frame 20, whereas the other wall 27 of the groove is inclined outwardly away from the wall 26. This provides a groove which is wedge-shaped in cross section into which the supporting portions of the spring unit are inserted.

The spring unit 10 is slightly longer than the distance between the bases 28 of the grooves 25 and in assembling the spring unit 10 with the frame 20, the spring unit, which is flat, is compressed longitudinally and/or bowed upwardly, as shown in FIGURE 2, so that the supporting portions thereof may be inserted into the open ends of the grooves 25. When the spring is released, the supporting or anchoring portions 14, 15 and 16 thereof become wedged between the walls 26 and 27 of the grooves 25 to hold the spring unit 10 in assembled relation with the frame 20.

When the spring unit 10 is loaded, as for instance by a person sitting on the seat, the bowed portion of the spring is deflected downwardly to lengthen the spring unit, whereupon the supporting end portions are wedged further into the grooves or rabbets 25. Also, the end portions of the spring unit come to rest on the horizontal or parallel walls 26 of the grooves 25 to restrain the spring unit from excessive downward deflection below the plane of the grooves 25.

In FIGURE 4, the spring unit 10 is shown in a slightly modified form. In this form of construction, the spring wire is bent to form a plurality of similarly disposed substantially rectangular loops 30 alternating with a plurality of oppositely extending loops 31 connected by straight portions 32. Supporting or anchoring end portions 33 are provided at one end of the spring unit. A similar supporting or anchoring portion 34 is provided at the other end of the spring unit and the ends 35 are arranged in longitudinal alignment with the portion 34 and also function as supporting portions for the spring unit 10. Otherwise, the structure is the same as shown in FIGURES 1 to 3.

In FIGURE 5, another slightly modified form of spring unit is illustrated. In this form of construction, the spring wire is bent to form a plurality of zig-zag loops 40 connected by straight portions 41. The supporting or anchoring portions are indicated by the reference characters 42 and 43 and the ends 44 also constitute supporting or anchoring portions. In other respects, the structure is the same as shown in FIGURES l to 3.

Usually, the spring unit 10 is covered by an insulating pad (not shown) of any desired construction and the entire structure will be covered by upholstery padding (not shown), as is customary in furniture of this type.

From the foregoing, it will be obvious that when assembled the inherent resiliency of the spring unit 10 will hold the latter firmly and securely in the frame and that no other fastening or anchoring means for the spring unit is required. It will likewise be apparent that the spring unit and frame may be assembled quickly and easily and that the number of component parts are so reduced as to approach the ultimate in structural simplicity. Moreover, the simplicity of the structure creates an economy in its manufacture, assembly and maintenance.

While several commercially practical forms of the invention have been described and illustrated herein somewhat in detail, it will be understood that various changes may be made as may come within the purview of the accompanying claims.

What is claimed is:

i. A spring construction comprising a spring unit, and a frame provided with spaced grooves with a horizontal bottom side and a diverging top side the open ends of said grooves confronting one another, said spring unit being longer than the distance between the open ends of said grooves, said spring unit being compressed longitudinally sufiiciently and the ends thereof being inserted I into said grooves whereupon the inherent resiliency of the spring unit will hold the same in assembled relation with said frame with the ends free to pivot downwardly into engagement with the horizontal side-s.

2. A spring construction comprising a normally flat spring unit, and a frame provided with spaced grooves having a horizontal bottom side and a diverging top side the open ends thereof in confronting relation, said spring unit being longer than the distance between the open ends of said grooves, said spring unit is bowed sufficiently to longitudinally compress the same and to permit the spring ends to be inserted into said grooves whereupon the inherent resiliency of the spring unit will hold the same in assembled relation with said frame with the ends free to pivot downwardly into engagement with the horizontal sides.

3. A spring construction comprising a fiat spring unit, and a frame provided with spaced grooves with a hori zontal bottom side and a diverging top side the open ends of said grooves confronting one another, said spring unit being longer than the distance between the open ends of said grooves, said insert spring unit is compressed longitudinally and bowed sufficiently to the spring ends into said grooves whereupon the inherent resiliency of the spring unit will hold the same in assembled relation with said frame with the ends free to pivot downwardly into engagement with the horizontal sides.

4. In a spring construction comprising a normally flat spring unit, and a frame, that improvement which comprises, grooves formed in spaced sides of said frame, said grooves being substantially wedge shaped in cross section and having their open ends arranged in confronting relation, said spring unit being longer than the distance between the open ends of said grooves, said spring unit being compressed longitudinally sufliciently to permit the ends thereof to be inserted into said groves whereby the inherent resiliency of the spring unit will force the ends of the spring unit into engagement with said wedgeshaped grooves to hold the spring unit and frame in assembled relation.

5. A device as described in claim 4 in which one wall of each wedge-shaped groove is shaped to restrain the spring unit from excessive movement under load in one direction.

6. A device as described in claim 4 in which one wall of each wedge-shaped groove is substantially parallel with the horizontal plane of the frame and adapted to be engaged by the spring unit under load to restrain the spring unit from excessive deflection below the plane of said grooves.

7. In a spring construction comprising a normally flat spring unit, formed by sinuously bending a spring wire into adjacent oppositely disposed loops, and a frame, that improvement which comprises, grooves formed in spaced sides of said frame, said grooves being substantially wedge shaped in cross section and having their open ends arranged in confronting relation, said spring unit being longer than the distance between the open ends of said grooves, said spring unit being compressed longitudinally sufliciently to permit the ends thereof to be inserted into said grooves whereby the inherent resiliency of the spring unit will force the ends of the spring unit into engagement with said wedge-shaped grooves to hold the spring unit and frame in assembled relation.

8. In a spring construction comprising a normally fiat spring unit, formed by sinuously bending a spring wire into adjacent oppositely disposed loops, and a frame, that improvement which comprises, grooves formed in spaced sides of said frame, said grooves being substantially wedge shaped in cross section and having their open ends arranged in confronting relation, said spring unit being longer than the distance between the open ends of said grooves, said spring unit being compressed longitudinally and bowed sufiiciently to permit the ends thereof to be inserted into said grooves whereby the inherent resiliency of the spring unit will force the ends of the spring unit into engagement with said wedgeshaped grooves to hold the spring unit and frame in assembled relation.

9. In a spring unit, a plurality of parallel rows of spring strip made of wire bent into sinuous form, the springs in adjacent rows being joined together by a straight portion of wire, alternate pairs being joined at opposite ends, all of said strips being flat so that all portions of the unit are in a flat plane with the ends in aligned relation, said spring strips being formed of rectangular loops which are oppositely facing and with the loops of the strips disposed in aligned relation and facing in the same direction.

References Cited by the Examiner UNITED STATES PATENTS 1,599,365 9/26 King et a1. 2671 1,868,514 7/32 Anstiss 245--6 X 1,901,720 3/33 Barwinkel 267 2,485,443 10/49 Hathaway 267110 2,678,685 5/54 Volsk 267-1 2,870,823 1/59 Staples 267-407 X 3,039,763 6/62 Staples et al 267--107 FOREIGN PATENTS 894,749 10/53 Germany. 337,414 10/30 Great Britain.

ARTHUR L. LA POINT, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,188,073

Herbert Schneider June 8, 19

ror appears in the above numbered pat- It is hereby certified that er the said Letters Patent should read as ent requiring correction and that corrected below.

Column 1, line 59, for "plain" read plan column 3, line 6 6, before "the" insert insert Signed and sealed this 15th day of February 1966.

(SEAL) Attest:

ERNEST W. SWIDER Attesting Officer EDWARD J. BRENN] Commissioner of Paten 

1. A SPRING CONSTRUCTION COMPRISING A SPRING UNIT, AND A FRAME PROVIDED WITH SPACED GROOVES WITH A HORIZONTAL BOTTOM SIDE AND A DIVERGING TOP SIDE THE OPEN ENDS OF SAID GROOVES CONFRONTING ONE ANOTHER, SAID SPRING UNIT BEING LONGER THAN THE DISTANCE BETWEEN THE OPEN ENDS OF SAID GROOVES, SAID SPRING UNIT BEING COMPRESSED LONGITUDINALLY SUFFICIENTLY AND THE ENDS THEREOF BEING INSERTED INTO SAID GROOVES WHEREUPON THE INHERENT RESILIENCY OF THE SPRING UNIT WILL HOLD THE SAME IN ASSEMBLED RELATION WITH SAID FRAME WITH THE ENDS FREE TO PIVOT DOWNWARDLY INTO ENGAGEMENT WITH THE HORIZONTAL SIDES. 